my $i = ord(4);
foreach my $c (3,2,1) { $i <<= 8; $i |= ord($c); }
our $byteorder = join('', unpack('aaaa', pack('L!', $i)));
s/(byteorder=)(['"]).*?\2/$1$2$Config::byteorder$2/m;


##</code><code>##

 172 byteorder (byteorder.U):
173         This variable holds the byte order in a UV. In the following,
174         larger digits indicate more significance.  The variable byteorder
175         is either 4321 on a big-endian machine, or 1234 on a little-endian,
176         or 87654321 on a Cray ... or 3412 with weird order !